This application relates to a magnetic read/write recording head used in disc drive applications. Specifically, the present invention relates to a method of fabricating a coil structure for use in a writer portion of a magnetic read/write recording head.
Standard recording heads are fabricated with a writer portion fabricated on top of a reader portion. Recording heads are used in magnetic storage systems to detect magnetically encoded information from a magnetic storage medium or disc and to write magnetically encoded information to the storage medium.
Presently there are two types of recording heads used in a disc drive of a computer device. First there is an inductive magnetic recording head which incorporates an inductive writer portion and an inductive reader portion. Second, there is a magnetoresistive recording head which incorporates an inductive writer portion and a magnetoresistive reader portion. Thus, regardless of the type of reader portion which is utilized in the recording head, the writer portion is an inductive writer portion.
A typical inductive writer of a recording head consists of one or more coil conductor layers protected by insulating layers and surrounded by an upper and a lower magnetic core (also called top and bottom poles or called top and shared poles) which are separated at the air bearing surface of the writer by a thin magnetic gap layer. The air bearing surface is the surface of the recording head immediately adjacent to the magnetic medium or disc. Fabrication of the coil layers typically involves planarizing the surface on which the coils will be positioned with either a photoresist process or a metallic layer and photoresist combination process. Individual coils are then positioned on the planarized surface and encapsulated with another photoresist layer to insulate and electrically isolate the coils as well as protect the coils from damage during subsequent processing steps.
Prior art recording devices typically include three or four coil layers. As coils are typically stacked several layers high, most insulating photoresist layers provide insulation and isolation of a coil layer and provide a planarized top surface by which a succeeding coil layer in the stack can be fabricated. Coil layers will typically form stepped surfaces in which the next coil layer is either larger than the previous coil layer, when the coil layers are formed upon a recessed bottom pole, or is smaller than the preceding layer when the coil layers are formed on a planarized bottom pole or extend above the recess portion of the bottom pole.
Fabrication of a writer portion of a magnetic read/write recording head is dictated by the physical fabrications limitations of the coils using conventional thin-filmed head process use.
In standard prior art applications, the magnetic coils are separated from one another on the same level by an insulating barrier which is approximately equal in width to the width of the magnetic coil. Likewise, the magnetic coils of adjacent layers are separated by an insulating layer approximately equal in height to the height of the inductive coil. Thus, a typical coil structure has a conductor/insulator cross-sectional area ratio of 40 percent.
There is a need for improving the conductor/insulator cross-sectional area ratio of a writer portion of a magnetic read/write recording head. In particular, there is need for a writer portion of a magnetic read/write recording head which will have a higher packing density of magnetic coils within a given area. A writer portion of this nature would produce a more efficient magnetic writer.